Additional requirement: Changed to code to make sure it only runs on dev channel (i.e. it'll self-disable if executed on a different channel).

Yes, we have CL in flight for that already: https://chromium-review.googlesource.com/#/c/414044/

Relegating to V1 since we'll revamp that code anyways.

We have ack from KIR: https://groups.google.com/a/google.com/d/msg/chromad/NpPRwR4FmeM/-bzTOQWXAgAJ

And requisition parameter has been enabled per https://codereview.chromium.org/2528923002/.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/platform2/+/e56edf619ec2a7cea8cbd81c2b90c93f30f2e937

commit e56edf619ec2a7cea8cbd81c2b90c93f30f2e937
Author: Lutz Justen <ljusten@chromium.org>
Date: Wed Nov 23 14:03:01 2016

authpolicy: Prevent startup on non-dev channels

During the initial testing phase of authpolicy prevent that it is run on beta
or release channels.

BUG= chromium:668455 
TEST=Emerges, verified that it runs on a testimage-channel

Change-Id: I2ddaae75d56fa2cba0d6c9cddf50cbce77ebea33
Reviewed-on: https://chromium-review.googlesource.com/414044
Commit-Ready: Lutz Justen <ljusten@chromium.org>
Tested-by: Lutz Justen <ljusten@chromium.org>
Reviewed-by: Thiemo Nagel <tnagel@chromium.org>

[modify] https://crrev.com/e56edf619ec2a7cea8cbd81c2b90c93f30f2e937/authpolicy/authpolicy_main.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9618887b3455dad36fabad59281659a02adeae26

commit 9618887b3455dad36fabad59281659a02adeae26
Author: rsorokin <rsorokin@chromium.org>
Date: Tue Mar 21 14:12:17 2017

Remove custom shortcut for Chromad

Remove ctrl-alt-shift-a for the Active Directory enrollment flow.
Let server decide type of enrollment.
Also remove "--enable-ad" command line flag

BUG= 668455 
TEST=manual

Review-Url: https://codereview.chromium.org/2736873004
Cr-Commit-Position: refs/heads/master@{#458398}

[modify] https://crrev.com/9618887b3455dad36fabad59281659a02adeae26/chrome/browser/chromeos/login/ui/webui_login_view.cc
[modify] https://crrev.com/9618887b3455dad36fabad59281659a02adeae26/chrome/browser/chromeos/policy/device_cloud_policy_initializer.cc
[modify] https://crrev.com/9618887b3455dad36fabad59281659a02adeae26/chrome/browser/ui/webui/chromeos/login/signin_screen_handler.cc
[modify] https://crrev.com/9618887b3455dad36fabad59281659a02adeae26/chromeos/chromeos_switches.cc
[modify] https://crrev.com/9618887b3455dad36fabad59281659a02adeae26/chromeos/chromeos_switches.h
[modify] https://crrev.com/9618887b3455dad36fabad59281659a02adeae26/ui/login/display_manager.js

bulk Verify of older or not-user-facing Chromad bugs